Select all characteristics of sea cucumbers. soft, elongated body ossicles are fused to form a rigid, shell-like test ossicles are reduced to microscopic elements rely on water vascular system for locomotion crawl using their long, flexible arms madreporite on aboral surface madreporite on oral surface internal madreporite small, immovable spines long, well-developed, moveable spines no spines.

1. Select all characteristics of sea cucumbers. soft, elongated body ossicles are fused to form a
rigid, shell-like test ossicles are reduced to microscopic elements rely on water vascular system
for locomotion crawl using their long, flexible arms madreporite on aboral surface madreporite
on oral surface internal madreporite small, immovable spines long, well-developed, moveable
spines no spines